This is a continuation-in-part application to parent application Ser. No. 07/115,935 filed Nov. 2, 1987, abandoned by the same inventors and having the same title.
This invention relates to an ice bank control system, and in particular to such a system for a beverage dispenser having a mechanical refrigeration system.
Ever since ice banks have been used to maintain a water bath at or near 32 degrees F. surrounding the ice bank, the control systems to maintain the ice bank, for the most part have been metal capsules filled with water. The freezing process caused expansion within the capsule thereby flexing a diaphragm and pushing a fluid in a capillary tube against a piston on the opposite end of the capillary tube to actuate a switch. These systems have been adequate over the years, however, being a mechanical type of system, they have problems of leakage, diaphragm wear, and general mechanical tolerances that sometimes make this type of control irregular in its operation. Since the water inside the capsule on these devices is enclosed, they all tend to overbuild an ice bank on the initial pull down, as the first ice crystal formation does not occur immediately, partially due to having a very slight pressure on the water in the capsule. After the initial pull down, the ice never completely melts within a capsule during normal operation and the temperature cycle becomes very consistent until wear or leakage in the system causes a change that generally builds a larger ice bank until complete failure, at which time, the water within the ice bank container completely freezes. To replace the control necessitates waiting for the ice to melt. In addition, when the ice bank container freezes completely, damage often occurs to the more expensive stainless steel water and syrup cooling coils, requiring replacement thereof.